Telegraphic receiving system by means of hertzian waves.



No. 773,340. Y I PATENTED OUT. 25, 1904.

0. ROGHBFORT.

TELEGRAPHIG RECEIVING SYSTEM BY MEANS OF HERTZIAN WAVES.

APPLICATION FILED AUG. 26. 1903.

NO MODEL.

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UNITED STATES Patented October 25, 1904.

PATENT OFFICE.

OGTAVE ROCHIEFORT, OF PARIS, FRANOE ASSIGNOR OF ONE-HALF TO. LA SOCIFITE ANONYME DELECTRICITE ET DAUTOMOBILES MORS,

OF PARIS, FRANCE.

SPECIFICATION forming part of Letters Patent No. 773,340, dated October 25, 1904. Application filed August 26, 1903. Serial No. 170,816. (No model.)

To all who/0e it may concern:

Be it known that I, OcrAvn Rocnnnon'r, a

citizen of the Republic of France,and a resident of Paris, France, have invented new and useful Improvements in Telegraphic Receiving Systems by Means of Hertzian Waves, which improvements are fully set forth in the following specification.

This invention relates to a telegraphic receiving system by means of Hertzian waves, and has for its object an improved method of reinforcing the action of the waves by a novel cohererer, termed the coherer-condenser, novel combinations of connections with a transformer and the novel receiver permitting of effecting these combinations.

It is possible to obtain a practical coherercondenser owing to the invention of the coherer-tube presenting a central rod.

The receiver here described is a novel receiver specially applicable to this reception by condenser-tube.

In the accompanying drawings, Figure l is a longitudinal section through the coherertube. Fig. 2 is a front elevation of a wheel formed by the winding of a single wire and adapted to constitute the contact in the filings. Fig. 3 shows the arrangement of a coherercondenser capable of automatic regeneration. Fig. 4 shows a modification of the coherercondenser tube. Fig. 5 relates to acondensertube capable of automatically decohering. Figs. 6 and 7 are diagrammatic views relating to bipolar resonators. Fig. 8 is a diagrammatic view showing the connections. Fig. 9 shows a modified arrangement of connections.

The coherer-condenser is based upon the following idea: Given a cohering-tube comprising three parts, two electrodes and a third part interposed between them and composed either of a single block of metal or of a collection of filings, take a third contact upon the central element either through one of the particles of filings or through the central block. The colierer-tube is thus divided into two distinct zones which communicate one with the other only when the I-Iertzian waves have traversed the whole of the tube, which amounts to this; a single tube will present two coherable gaps instead of one, while at the same time only presenting (from the point of view of the Hertzian waves) two electrodes. In such a tube its two electrodes may be connected by the continuous secondary wire of an induced or resonant solenoid, and the presence of the central contact will permit of forming two circuits each presenting a definite gap coherable by the Hertzian waves. A tube of this kind may be constructed in various ways. The most practical form is one derived directly from the central rod tube shown in Fig. 1.

A conducting-rod a 7) traverses two insulating-cylinders 0 and (Z. A conducting-ring c is arranged around the cylinder 0. A ring f is arranged around the cylinder cl. Between these two tubes and directly connected to the central rod (0 b is a cylinder g. Metal filings are placed in the two equal spaces comprised between g and e on the one hand and between 9 and f on the other. The cylinder g is formed of the same metal as the filings or of a metal not cohering with it, so that it constitutes a sheath or skin of these filings. The outer radius of the cylinder 9 and that of the two rings a fare equal and are fitted within the insulating tube, which constitutes the outer covering of the coherer-tube. A contact it is connected by a conducting-wire to the ring f, and a contact Z: is connected to the ring 6. These are the contacts upon the two electrodes. A third conductingwire, soldered to the rod (0 Z), is joined to a third contact Z of annular form. This is the contact on the filings.

The cylinder g may advantageously be replaced, Fig. 2, by asingle wire forming a kind of wheel, the radial arms of which are fixed at the middle of the rod (07) and at an equal distance from the two electrodes f and e. In this case the filings instead of occupying two separate recesses occupy the same recess. The

wire constituting the wheel g should be of the same metal as the filings of the tube and does not constitute an obstacle to the meeting of the particles of filings, which thus constitute a single mass.

The coherer-tube may be capable of automatic regeneration. It is only necessary, as indicated in Fig. 3, to separate theelectrodes a and f and to arrange in the space comprised between the two electrodes two wheels r g. The space g y then forms a reservoir for the filings.

A third example, Fig. 4, maybe constituted by three cylinders, the central cylinder r/ of the same metal as the filings, the two other cylinders being of the same metal as that selected for the electrodes of the tube. The contacts will then be Z: Z A directly upon the tube.

These three constructional forms practically sum up the arrangements which may be ado pted for the condenser-tube. It should of course be understood that these forms are reversi ble-that is to say, in the same tube the central portion may be of electrode metal and the two extreme portions of the same metal as the filings.

A condenser-tube may be automatically decoherable. Let us consider, for example, a steel-aluminium autodecoherer-tube as shown in Fig. 5. c and (Z are two steel electrodes adapted to slide in a tube. 0 is aballof aluminium of ellipsoidal form. The small axis of the ellipsoid is traversed by a rod issuing from the tube at ma. The portion m carries a terminal and n carries a metal rod 71.. Under the influence of two springs c and (Z bear against the aluminium. and by rotating the rod 11 by a certain angle the pressure of the springs may be diminished. This is the adjustment of the tube. Each of the two electrodes presenting a contact and the central mass g having a third the tube constitutes an autocoherer and adjustable tube. It the two electrodes c and (Z are assumed to be fixed, the aluminium ball should be replaced by a drop of mercury, in which the rod m w plunges. This rod 912.1], which is of iron, being provided with a contact, a mercury-drop autodecoherertube is obtained, which is also a condensertube. These examples will show how such tubes may be constructed. Their purpose is hereinafter described.

The bipolar resonator is shown in Figs. ('3 and 7. 1n Fig. 6 the bipolar resonator is formed by two solenoids 1 2 3, 1 2 3. These two solenoids are connected at the points 33, and the two solenoids as a whole may be considered as constituting one only, in which the winding 2 3, 3 2" 'forms the primary of a high-tension coil, the secondary ol which is formed by the two solenoids 1 2 3, 3 2 1 as a whole. The two poles of the primary are 2 Q. The two poles of the secondary are 1 1. The second form, Fig. 7, is that of a single solenoid 1 2, 2 1, in which the part 2 2 is considered as the primary and the solenoid 1 1 as a whole as the secondary or a hightension coil, 2 2 being the extremities of the primary poles and 1 1 the extremities at the poles of the secondary. This form of hightension coil, termed the bipolar resonator, constitutes an appliance for regulating the tuning for the receptions and emissions in Hertzian telegraphy.

Assuming that the second form, Fig. 7, is employed for adjusting the tuning in the novel means for reception by means of the coherer-condenser, the diagram of the connections is then as follows: If A A T T represent the bipolar resonator and Z: l 71 the condenser-tube, Fig. 8, Z; and 7e. are the contacts of the two electrodes and Z the contact upon the filings. hen a Hertzian wave strikes the antenna, a current is developed in the primary A T. This current will give rise to an induced secondary current in A T, and at A and T will appear two potentials of contrary sign at each moment. If A/l and T7. are joined, the induced tensions in A and in T, which are of contrary direction, will cohere the 'filings in the tube when a Hertzian wave strikes the antenna. A relay 1:, a resistance r, and a shunt t, which is adjustable, are provided. The resistance r and the shunt x together constitute the potential-reducer, the use of which has been indicated by Captain Ferric of the French military telegrapl'iic service. The arrangement is completed by a battery p and a milliampere-meter the latter serving to indicate to the operator the correct adjustment of the receiving system.

The electrodes 7.: and b are each connected to the positive pole of the battery by the intermediary of a self-induction coil 1. and v1. The adjustable resistance 1- is connected to the negative pole of the battery and to the outlet 1? of the frame of the relay. The admission ;1 of the relay-frame is connected to the outlet of the milliampere-meter and the admission to the milliampere-meter to the terminal l corresponding to the contact in the filings. The shunt s is connected to the outlet in of the relay on the onehand and to the positive pole of the battery on the other hand.

Assuming that owing to the action of the Hertzian waves an ind ucing-current traverses A T, the induced wave will traverse A T. At A and T will appear two tensions of contrary direction, and the filings in the tube will be cohered. The resistance between the electrode 7'. and the mass of the filings connected to Z will fall, and the current of the battery 7) is able to take the path 7) w 2' g :1 1' the frame of the galvanometric relay being caused to deviate in a certain predetermined direction and this inversely proportionately to the entire resistance of the circuit previously indicated and to the electromotive 'force of the battery diminished bythe shunt s. In the same manner, if we consider the electrode 71, the current of the battery p, owing to the cohering of the tube Z, will traverse the circuit 79 o h Z g y 00 r p, and the action of this battery-current assists in producing the rotation of the galvanometric frame in the same direction as before. The relays should therefore be less sensitive than a galvanometric relay placed upon an ordinary circuit in which there are the same filings, electrodes, and Hertzian action. In other words, the utilizatibn of the action of this Hertzian wave is increased by the relay.

Fig. 9 represents a modification in which it is not necessary to employ a self-induction coil. In this case the current proceeding to the two electrodes passes through the solenoid. The point .2 of the solenoid at Zero tension is connected to the positive pole of the battery 19 either directly or by the intermediary of a self-induction coil, and this form is similar to the first, with the exception that with this arrangement the high-tension silent discharges of the bipolar are received directed without possibility of loss at the electrodes k and ll. of the tube.

In the employment of reception by condensing-tube and by bipolar resonator for obtaining tuning for the reception with a predetermined wave length the bipolar resonator employed varies with the length of wave which it is desired to obtain of the form This length wave depends upon the expression ML (1, L being the self-induction, C the capacity of the circuit. We will consider the entire induced circuit A A T T h Z 70. The capacity of the tube will enter into the value of C and also the self-induction of the solenoid A A T T into the value of L G secondary. This value of L C secondary may here be determined by calculation. We will consider the antenna and earth inductor-circuit A T. The capacity of the antenna situated at A of the earth at T will be the unknown primary C. The self-induction of the portion of the solenoid from A to T and also that proper to the antenna and to the earth will be the unknown primary self-ind uction; but by-suitably regulating the points A and T it is possible by trial and error to arrive at a value of the product L C primary exactly equal to the product L C secondary which we have given ourselves. There are therefore only two points to search for methodically in order to arrive at the regulation of the length of reception-wave, having two values perfectly capable of measurement at our disposal for the secondary circuit which we may give ourselves of a definite power. In the case of Fig. 9 the point Z will always have to be sought both upon ,A T and between these points.

, The foregoing description at once shows the very great advantage of the condensertube. Hitherto in order to render it possible to employ a secondary circuit for the reception of Hertzian waves by the indirect method it was necessary either to divide into two this secondary circuit and to arrange the tube in the middlethat is to say, to have two secondary circuits or to interpose a condenser in a gap made in the secondary circuit. This is a system which renders the condenser unnecessary, thereby making a single secondary circuit sufficient, which may also, if desired, be combined with the primary circuit and which, other things being equal, increases in a large proportion the utilization of cohering for the action produced upon the relay.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A coherer, comprising a tube, two electrodes, a third element between them, and a contact on the third element, in combination with a solenoid having a secondary wire connecting said electrodes, and two circuits each including said third-element contact and presentingfa gap coherable by Hertzian Waves. 2. A coherer, comprisingaglass tube, electrodes at the extremities thereof, metallic rings in said tube and connected with said electrodes, a third element between said rings, insulating portions within said rings, an exterior metallic ring, a central metallic part, and a conductor connected with said exterior ring and central part.

3. A coherer, comprising a glass tube, two

electrodes, metallic portions in said tube andv connected with said electrodes, and two metallic wheels between said portions,said wheels being composed of wire.

tions between said electrodes and the terminals of the secondary of the resonator, a battery, connections between the electrodes and the positive pole of the battery, self-induction coils between the electrodes and said positive pole, a relay, a shunt connecting one pole of said battery to the outlet-post ofsaid relay, a resistance connecting the other pole of said battery to the outlet-post of the relay, a connection between the inlet-post of the relay and the intermediate element of the coherer, and a milliampere-meter in said lastnamed connection.

5. The combination of a coherer, comprising a tube, electrodes, and an element between said electrodes, a bipolar resonator, connections between said electrodes and the terminals of the secondary of the resonator, a battery, a direct connection between the positive pole of the battery and the solenoid IIO III 5 the outlet-post of said relay, a resistance con necting the other pole of said battery to the outlet-post of the relay, a connection between the inlet-post of the relay and the intermediate elenientof a coherer, and a milliamperemeter in said last-named connection.

in testimony whereof I have signed this specification in the presence of two subscribing Witnesses.

OOTAVE ROCHEFO RT.

Witnesses:

(:nrnonen E. Liem, EMILE LEDRE'I. 

